All Espoma® products are 100% organic. Espoma® Organic Bat Guano is a natural source of nitrogen, which helps plants develop a deep green color. It is also a good source of phosphorus, promoting root growth and blooming. It comes from wild insect-eating bats in a unique cave environment in the southwestern United States. Use it anywhere in your garden, indoor or outdoors, by applying it directly onto the soil or making a fertilizer tea.